With the ever increase of optical character reading and bar code reading of mail great efforts have been expended to manufacture mail with the address and bar code information easily visible. If, for example, a company such as a bank or a direct mail advertising company could produce a plastic windowed envelope or a plastic envelope which could allow the address or bar code information on the contents to show through then advantage could be taken of the generic envelope. With such a generic nature, the significant cost savings on envelopes which would be desirable if a mail sorting system could have a high speed and efficient aperture assembly to eliminate glare from the optical character reader and bar code reader light and facilitate the viewing by an optical character reader or bar code reader through the plastic to the contents inside.